As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AS TAKEOFF POWER WAS APPLIED, THE RIGHT ENGINE N1 INDICATION WOULD NOT INCREASE ABOVE 80 PERCENT. CREW ABORTED TAKEOFF AND RETURNED TO THE GATE. MAINTENANCE REPLACED THE N1 TACH GENERATOR AND N1 INDICATOR FOR THE RIGHT ENGINE. ENGINE WAS RUN TO TAKEOFF POWER. OPERATIONAL CHECK OK.